Justin Bieber has dedicated a song to Mariah Yeater.Neil Mockford/FilmMagic

Mariah Yeater had falsely claimed that Justin Bieber was the father of her baby. (Bauer-Griffin)

Justin Bieber has penned a song on his upcoming album dedicated to Mariah Yeater, the 20-year-old fan who claimed to have had the singer’s baby after a tryst with the pop star in a backstage bathroom.

“There’s a song about that girl that said she was gonna have my baby, Mariah Yeater,” Bieber told reporters last night at an event in London previewing his album “Believe,” which will be released June 19. “There are songs about things I’m going through. I wrote songs about different situations.”

Yeater alleged last November that her baby boy Tristyn, then three-months-old, had been conceived when she met Bieber following a Los Angeles concert and had sex with him in a backstage bathroom. The 20-year-old blonde demanded that the “Baby” singer take a paternity test and pay $260K in child support.

Bieber quickly went public to refute the claims, telling the “Today” show that he had “never met the woman.” He added in an interview, “I think it’s crazy because every night after the show I’m gone, right from the stage to my car so it’s crazy that some people want to make up such false allegations. But to set the record straight, none of it is true.”

Shortly after the hubbub, Yeater’s ex-boyfriend came forward, claiming paternity of the baby and telling the website RumorFix.com that Yeater had lied “because she wanted a $50,000 payday.” He explained, “She just picked [Bieber], because she thought he was famous and all and thought she could get a lot of money by telling the magazine Justin was the father.”

Bieber apparently still holds some anger over the incident.

In addition to writing the song, Bieber took to Twitter this weekend to address Yeater. He wrote, “‘Dear mariah yeeter … we have never met … so from the heart i just wanted to say….” He then linked to a clip of Sacha Baron Cohen as Borat saying, “You will never get this.”

While telling reporters about the Yeater song, Bieber also explained that he is not yet sure if it will appear on the album.

“We’ve recorded like 40 songs,” Bieber said, according to BBC News. “Every song has a piece of me … It’s so cool to do different styles and step out of my comfort zone.”